Mullaperiyar: Is the light in the tunnel itself?

P N Venugopal09/06/2014

Mullapperiyar Dam (Pic: Rameshng at ml.wikipedia.org)

A five-judge constitution bench headed by supreme court Chief Justice R M Lodha, on May 8, struck down a law enacted by the state of Kerala regarding the 120 year old Mullaperiyar dam positioned across the Periyar river in the Western Ghats. This verdict will now enable Tamil Nadu to raise the water level of the dam to 142 feet from the existing ceiling of 136 feet. The dam, though situated in Kerala is owned by the government of Tamil Nadu. The immediate and tangible effect of this will be the inundation of 7158 hectares of forest land in the Periyar Tiger Reserve and the low lying areas of Kumali town and portions of the tourist centre, Thekkady. Kerala government has decided to file a revision petition.

Concerns of safety of the masonry dam had always troubled the people and the government of Kerala and in 1979 the Central Water Commission had advised a top level of 136 feet which was being maintained till date. However in 2006 the Supreme Court allowed Tamil Nadu to raise the water level to 142 feet. The Kerala legislative assembly responded by unanimously passing the Kerala Irrigation and Water Conservation (Amendment) Act, 2006, limiting the Full Resorvoir Level (FRL) of 22 dams in Kerala including Mullaperiyar. The court struck down this legislation saying it breached established constitutional limitation - separation of powers.
This law was an attempt by the Kerala assembly to overreach the 2006 judgment which had allowed increasing the water level to 142 feet, the constitution bench said. "State of Kerala is restrained by a decree of permanent injunction from applying and enforcing the impugned legislation or in any manner interfering with or obstructing the state of Tamil Nadu from increasing the water level to 142 feet and from carrying out repair works as per the court's 2006 judgment."

The Kerala assembly's attempt was by no means an effort to confront the supreme court. Ever since the collapse of Machchu-2, an earthen dam across the river Machchu in Gujarat in 1979, resulting in massive loss of life in the town of Morvi, the people of Kerala have been apprehensive of the safety of the Mullaperiyar dam. It is a gravity dam constructed with rubble and a mixture of lime and surki ( burnt brick powder) paste. Gravity dam supports the reservoir by its weight and sheer gravity. The dam, over the decades of its existence, had developed massive leaks and the 'surki' was oozing out. The apprehension was that the dam was losing its weight and could collapse anytime, especially during the typically heavy monsoons of Kerala when the water level would go very high. Any breach in the wall would spell utter disaster for the five districts of Idukki, Pathanamthitta, Kottayam, Alappuzha and Ernakulam, directly affecting more than 80 lakhs people

There are innumerable instances of one state of the Indian federation having properties in another state. But Mullaperiyar is perhaps the only instance of one state having a full fledged dam in another state, in a river that flows entirely through that state and still enjoying full autonomy over the dam. All other water disputes are over the quantity of water to be shared. Mullaperiyar is unique in one more sense; Kerala is not worried over the quantum of water Tamil Nadu gets, but only about the security of its people. How it came about is history that goes back to the 19th John Pennycuick. Initially in the British Indian Army, he shifted to the Public Works Department (PWD) and was fascinated by the rivers emanating from the Western Ghats, traversing through the princely state of Travancore. Travancore was also blessed with two monsoons, the South West and the North East and the water in the Periyar was not being put to use in any appreciable manner. On the other side of the high ranges was the province of Madras, served with only the North East monsoon and starving for water. Periyar emanates from the Sivagiri peak of the Western Ghats in Kollam district in Kerala and after traversing through 186 km, the tributary Mullayar joins it. Periyar runs through 232 km traversing the Idukki and Ernakulam districts before draining into the Vembanad lake. Why not divert the water from Periyar to the east, to the arid lands of the Ramanad kingdom- a part of the Madras Presidency- Muttu Arula Pillai, the Prime Minister of the Raja of Ramnad, thought. The idea was shelved due to lack of funds and technical know how. It was revived in the late 1860s and Pennycuick along with another engineer Major Ryves drew up the plan for the dam.

However, the mountain creek where the river was to be blocked and the land which would be submerged by the barrier belonged to Travancore. Pennycuick pressurised the Madras Presidency government to intervene. The Maharaja of Travancore agreed, either because he thought his state had more than enough water, or because he could not withstand the pressure from the British who were after all his masters too. Thus a lease for 999 years was signed in October 1886 covering 8100 acres with Rs 5 as rent per acre, per annum. The dam was to be constructed by the Madras government, the height of the dam was to be 155 feet, and a tunnel was to be constructed to reach the water to the Vaigai river. The Mullaperiyar dam was commissioned in 1895. After independence, Travancore, Kochi and Malabar were united to form the state of Kerala and the onus of honouring the agreement was squarely on Kerala.

Mullaperyar Dam at the time of construction (Photo: Wikipedia.org)

The water from Mullaperiyar has been irrigating about 2,17486 acres of land in five districts of Tamil Nadu, viz Theni, Madurai, Sivaganga, Dindigul and Ramanathapuram and also generating electricity since 1970. The lease rent was enhanced to Rs 30 per acre and thus the government of Kerala gets approximately Rs 10 lakhs per annum including the surcharge on the electricity generated.

Not the quantity of water, but the security of the dam being the bone of contention between the two states, several studies have been conducted by various agencies including the Central Water Commission, the Delhi and Roorki IIT etc. the latest such study was by the supreme court nominated Empowered Committee (EC) headed by Justice A S Anand, the former Chief Justice of India. The study reports of each committee vary substantially and each party has been upholding the particular report which is perceived to uphold their interest.

The Kerala government had put forward the proposal of decommissioning the present dam and constructing a new dam slightly below the present dam site. Environmentalist in the state was up in arms about the new proposal as a new dam was bound to upset the ecology of the sensitive Western Ghats and result in the ruination of virgin forests. And moreover how many new dams will have to be constructed in the remaining 870 years of the lease, they ask. Tamil Nadu rejected the proposal outright, not getting into the details and maintaining its rigid stand that the Mulla dam is up and steady and will continue to be so for centuries to come.

However the EC has suggested the construction of a new tunnel for carrying water from the dam to Vaigai river, a proposal which perhaps is the seed of a mutually agreeable way out. The present tunnel is at a height of 106.5 feet from the bottom. So a massive quantity of water remains in the dam no matter to what extent the water level is increased. And this water is not put to any specific use at any point of time. Of course, some water has to be there in the reservoir for ecological purposes and studies done by the sub committee suggests a minimum of 50 feet of water, says Justice KT Thomas, who was a member of the EC, in his book on Mullaperiyar. This means huge quantity of water that is stored between 50 and 106.5 feet remain useless at present. So a tunnel at 50 feet would to a large extent overcome quite a number of contentious issues, it is suggested. Justice Thomas writes that the chairman of the EC asked the technical members of the committee, Dr C D Thatte and Mr D K Mehta to study the possibilities of a new tunnel and that the studies pointed to the possibility of a new tunnel being a tool to settle the dispute between the two states. The committee recommended that more studies can be done if both Kerala and Tamil Nadu agree. The supreme court too has suggested that the verdict is not an obstacle to the two parties exploring the possibilities in this direction. The idea of an alternate tunnel was first presented to the public domain by Prof C P Roy, a former chairman of Mullaperiyar Samara Samithi. "Construction of an alternate tunnel is the way out," says Prof. Roy. "Tamil Nadu will get water and Kerala the confidence that there will not be a deluge."
If the tunnel is possible technically and does not adversely impact the environment, the natural corollary would be that the height of the water level in the can be further reduced, meaning less pressure for the old walls and relief from anxiety and panic for millions in the downstream of Periyar. This will ultimately be a political solution and statesmanship of the highest acumen is called for.